Sharif Digital Repository

In this study, three dimensional analysis of soil slopes subjected to dynamic loading was conducted in order to investigate the interaction of soil-pipe system. For modeling of soil behavior, strain-dependent nonlinear elasticity along with Mohr-Coulomb plasticity was defined to the material and elasto-plastic behavior was used for the pipes. For dynamic modeling of soil slopes and analysis of buried pipelines, a Finite-Element-based software, ABAQUS was utilized. In this regard, first the numerical model was calibrated and verified based on the results obtained by physical shaking-table tests on a soil slope. Afterwards, a comparison was made between the results of numerical models and some... 

In the history of philosophy, the discussion of moral responsibility is tied to "Free Will" metaphysical controversies. Philosophers generally expect that people have "alternative possibilities" -that require them not to be bound to a deterministic situation- or if they don't have such possibilities, at least be able to "control" their actions, and if they don't know all aspects of what they do, at least not to be in ignorance about that, according to Aristotle. In the case of having such minimal possibilities, it is that one can be considered morally responsible for his or her actions. This broad conception of moral responsibility can be traced from Aristotle's discussions in the... 

In this project alumina-zirconia-ceria nanocomposite with 80% mol alumina (0.2Ce0.1Zr0.9O2-0.8Al2O3) was produced by solution combustion synthesis method. In the mentioned method, optimal fuel with composition of 75% urea, 25% ammonium acetate, and stoichiometric amount of glycine (0.75U-0.25AA-1G) was used. Moreover, ammonium nitrate as aid combustion was added to optimal fuel. In order to calcinations, nanopowder obtained from combustion synthesis was heated to 500°C for 1 hour and kept at this temperature for 2 hours. To complete heat treatment, the nanopowder was heated to 1150°C for 2 hours and 10 min and kept at this temperature for 2 hours. Then the specimens were pressed at pressure... 

Tipping points occur in diverse systems in various disciplines such as ecology, climate science, economy, sociology, and engineering. Critical thresholds in system parameters or state variables at which a tiny perturbation can lead to a qualitative change in the system exist in many subsystems in complex systems. These thresholds are called tipping points, and these subsystems are called tipping elements. Additionally, many systems with tipping points can be modeled as networks of coupled multistable subsystems. Domino-like tippings are called tipping cascades. Considering that these tipping cascades are primarily unprecedented, it is essential to study the dynamics and control of these... 

Recovery of heavy metals from Hydrocracking spent catalyst was studied in a bioreactor by Acidithiobacillus thiooxidans. At first adaptation of microorganisms was done with spent catalyst in shaker flask. Using central composite design (CCD) the experiments were conducted in order to find optimized condition. Three factors such as particle size, pulp density and aeration rate were examined. Reduced cubic models were established to identify the relationship between the recovery percent of the metals and the variables. The results showed the maximum extraction of 87% Mo, 37% Ni and 15% Al were achieved after 7 days of batch process in bioreactor. The optimal values of variables were pulp... 

Selection of muscle activation pattern to reach a specific goal by considering the complexities of neuromuscular system and the way it overcomes these complications, are of researchers’ space interest in motor control. One proposed solution for resolving these complexities is the concept of simple module (synergies) that suggests the combination of them leads to more complex activities. In the present work, the existence and arrangement of synergies in the lumbar spine have been studied. For this purpose, a model with 18- muscles at level of L4-L5 under utilized in the static condition. In order to obtain the muscular and stability synergies, a biomechanical model predicting muscle... 

The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to... 

In the past few decades, shaking tables are widely used to evaluate system response of structures under seismic excitations. These devices are used without any fundamental research performed on a shaking table system as an entity model. In most of these studies for simplicity, it is assumed that there exist no considerable vibration and displacement around the shaking tables, and no attention is paid to the peripheral substances such as soil settled under the foundation.
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have... 

Out of several ground improvement techniques available, stone columns have been widely used. This technique has been successfully applied to increase the bearing capacity and to reduce the settlement for foundation of structures like liquid storage tanks, earthen embankments, raft foundations, etc., where a relatively large settlement is permissible. This technique has, generally, been proven successful in increasing the stiffness of weak soils, upgrading their safe bearing capacity, and reducing their total and differential settlements, as well as speeding up their consolidation process. The beneficial effects of stone column installation in weak deposits is manifested in the form of...